Andrew Dodt continues to lead the Australians, adding a second consecutive round of 70 to be in a share of 10th position and just three shots from the lead.
Scott Hend as the only other Australian to make the cut despite struggling to a second round of 75 to be at 2 over and made the cut on the number.
Of the leaders Belgian, Pieters, had finished his opening round with a bogey after finding water and he dropped another shot on the third hole of his second round, but then gained that back on the next hole before powering his way to the top of the leaderboard with further birdies on the ninth, 12th and 17th holes.
“Today was much less stressful than yesterday,” said Pieters. “I hit a lot more greens today. I didn't make as many putts as yesterday but that's always going to happen. So I'm quite happy about today.”
Pieters, who finished as Europe’s top points scorer on his debut at last year’s Ryder Cup, was joined at the summit by Jamieson, who recovered from dropping three shots in his opening three holes to post seven birdies in his round of 70.
Former Ryder Cup player Molinari, who has four top ten finishes at Wentworth, then made it a three-way share on seven under par when he birdied the two closing par fives for a round of 70.
“I didn't play amazingly well but I made some good up-and-downs to keep the round going,” said Molinari. “And then obviously I finished very well on 17 and 18.
“I’ve been in position before here but hopefully the ending will be different.”
The trio are one shot clear of Germany’s Max Kieffer who climbed the leaderboard after picking up five shots in four holes from the 11th in his round of 68.
The chasing pack is an impressive one, with Open Champion Henrik Stenson (71) Ryder Cup legend Lee Westwood (69), 2015 BMW PGA Champion Byeong Hun An (69) and seven-time European Tour winner Branden Grace (71) sharing fifth place on five under par, just two shots back.
A crowd of 24, 716 people – the second largest Friday crowd in the event’s history – watched the second round of action at the prestigious Surrey venue.
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